Foundations for a shed

[clio57]

I'm not a DIY'er but want to have a bash and making a foundation for an 8' x 8' shed.

When it says I have to compress hardcore before I put concrete on top do I have to hire a machine to do it or what?

The ground is full of old roots and rocks and stuff so I was hoping that the concrete will be above ground level.

Basically any practical advice on the best way forward would be appreciated.

[Clanad]

Here in the U.S., I've built or helped build several storage units such as you're contemplating.

First, if the ground on which you plan to build is fairly level and firm, the best method would be to add about 4 to maybe six inches of sand extending perhaps 6 inches beyond the outside limits of your shed's base. This should be compacted, and a rented compactor is best. However, there are hand compactors one can buy, rent or even build that will do the job. Use a 2 X 2 piece of lumber 4 or 5 feet long and screw an 8 X 8 inch piece of plywood to the base and simply walk over the area "tamping" the sand until firm. Make sure the sand is dampened, watering it with a hose if neccessary.

Next, build a grid with concrete rebar reinforcing rods. The rebar cuts easily with a common hacksaw. It should be elevated above the sand an inch or so and there are spacers available at DIY stores for the purpose. Using any common wire (here, in ranching country, we use baling wire from our hay balers) tie the rebar at the intersection of 8 to 10 inch squares. Surround the area to the size of the base of your shed with a 2 X 4 frame to hold the concrete and stake it down every 2 feet or so, nailing the frame to the stakes. (The stakes need to be on the outside of the frame). Pour the concrete, and level it and smooth it with a float to get a good surface. You should be able to start on the shed after a day or so.

By the way, you'll require about 35 cubic feet (about 4 cubic yards) of concrete for a 4 inch deep base plus any you would like for an approach to the main doorway.

Last though... imbed about 4 6 inch by 5/8ths inch galavnized bolts thread side up in the edges of the new concrete to secure the base of the shed. The base plate can esily be drilled to receive the bolts which can then be fitted with a large washer and nut... Best of luck!

[clio57]

Thanks Clanad. Will pass on your response to the men in my life who will be doing the physical work. I think I could cope with tamping the sand. I won't need to hire a compactor for that. I hadn't thought of sand and was thinking of hard core rubble.

It's going to be a few weeks I guess before we get land prepared to start work but I'll let you know.

Thanks again.

[mjwman]

I have a shed.
I bought when I moved here in 1984.
I laid a concrete base on hardrcore and it was fine.
A few years later I realised it was in the wrong place so I got some old paving slabs from the local council and laid those level where it was to be re-positioned,
It has been there for what, 20 years and it is stable and fine!
The moral of the story is .. don't go mad just provide a stable base.